1. Field of the Invention
The present invention relates to an optical semiconductor lighting apparatus.
2. Description of the Related Art
Compared with incandescent light and fluorescent light, optical semiconductors, such as LEDs or LDs, consume low power, have a long lifespan, and have high durability and high brightness. Due to these advantages, optical semiconductors have recently attracted much attention as one of components for lighting.
Typically, in the lighting apparatuses using such optical semiconductors, heat is inevitably generated from the optical semiconductors. Therefore, it is necessary to install heat sinks at heat generation sites so as to discharge the generated heat to the outside.
As the optical semiconductors have recently become popular and have been mass-produced, unit costs of the optical semiconductors have also been lowered. Therefore, the lighting apparatuses using the optical semiconductors have tended to be used for high power industrial lighting, such as factory lighting, streetlight, or security light.
In the lighting apparatuses using the optical semiconductors, which are used for the high power industrial lighting, generation of heat increases in proportion to the size and power of the lighting apparatuses. As a result, it is necessary to increase the capacity and volume of the heat sink so as to demonstrate excellent heat dissipation performance.
Generally, heat sinks mounted on the lighting apparatuses using the optical semiconductors are manufactured by die casting or the like, such that the heat sinks are integrally or detachably connected to a housing. However, the heat sinks manufactured in such a manner increase the total weight of the product and increase the manufacturing costs and the amount of raw materials used.
In particular, in the case of the conventional heat sinks manufactured by die casting, heat sink fins cannot be formed to have a thickness below a predetermined reference value due to characteristics of the manufacturing method thereof. Hence, a heat dissipation area intended at a limited site is narrow, and the volume and size of the heat sink is increased if a plurality of heat sink fins are formed for securing a sufficient heat dissipation area.
Meanwhile, in this regard, if a heat sink is manufactured in a shape of a heat sink plate by using a sheet (thin plate), a sufficient heat dissipation area may be secured. However, due to the structural limitation that the heat sink should be arranged in a line contact manner, heat generated from optical semiconductors may not be effectively transferred and discharged to the outside.
Furthermore, in the lighting apparatus using the optical semiconductor, a circuit board, on which the optical semiconductors are disposed, is connected to a heat sink, and the circuit board is embedded in a housing. An optical member, such as a lens, which is installed in the housing, allows light from the optical semiconductors to be irradiated more widely or narrowly.
In most cases, the lighting apparatus using the optical semiconductor is disposed on a rectangular or circular circuit board for convenience of manufacturing, and a housing is also rectangular or circular.
However, in view of the number of the lighting apparatuses arranged per unit area in order for high power, if a large number of lighting apparatuses are arranged, the total weight and volume thereof are increased due to the limitation of the structural shape.